Solution Step 0/0
There are 10 bags of coins (the number of coins in each bag is the same).
Nine bags contain gold coins, and one contains counterfeit coins. The weight of a real gold coin is 5 grams. The weight of a counterfeit coin is 4 grams.
How in one weighing on a scale (scales are weighed to the nearest gram) determine which bag contains the fake coins? Only one of the following actions would help in this. Which one?
Nine bags contain gold coins, and one contains counterfeit coins. The weight of a real gold coin is 5 grams. The weight of a counterfeit coin is 4 grams.
How in one weighing on a scale (scales are weighed to the nearest gram) determine which bag contains the fake coins? Only one of the following actions would help in this. Which one?
Explanations
Let's number the bags from 1 to 10. From the 1st bag we take 1 coin, from the 2nd one - 2 coins, from the 3rd bag - 3, and so on up to 10 coins. A total of 55 coins.Let's weigh these coins. If all the coins were gold, they would weigh 275 grams. If, during the weighing, the overall weight is 1 gram less, i.e. 274 grams, then counterfeit coins are in the 1st bag, if 2 grams are “missing“ - then in the 2nd bag, and so on up to 10.
Check Split the bags
Check Weigh 1/2 of each bag
Check 7 coins from the 7th bag
Check Odd vs even bags
